Demand mixing and dispensing machine



y 1962 D. E. TRUMBULL ETAL 3,042,264

DEMAND MIXING AND DISPENSING MACHINE Filed Oct. 1, 1959 5 Sheets-Sheet lINVENTORS 004 440 4'. raw/M0041.

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DEMAND MIXING AND DISPENSING MACHINE s Sheets-Sheet 2 Filed Oct.

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DEMAND MIXING AND DISPENSING MACHINE Filed Oct. 1, 1959 5 Sheets-Sheet 3INVENTORJ' 0044420 5. meow/e041. flaw/o4 u. 05w: GED/{ 6f 6f PVAFS July3, 1962 D. E. TRUMBULL ETAL 3,042,264

DEMAND MIXING AND DISPENSING MACHINE 5 Sheets-Sheet 5 Filed Oct.

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INVENTOR. DOA/4Z0 6 6- Pal-w.

Arroeye-rs Unite rate This invention relates to the mechanical arts.More particularly, it relates to mixing and dispensing equipment.

Recent advances in the chemical arts have resulted in resin basedcompositions useful as sealants, potting compounds and caulkingcompounds. Typical examples of such compositions are the polysulphidedihalide products. Such compositions are generally obtained by mixing together a monomeric resin and the like component with an appropriatecatalyst or accelerator component which causes the resin to rapidlypolymerize and cure. In some instances additional components such asfillers, pigments and the like may also be included in the mix. Becauseof the speed with which the resin is made to polymerize, it is usuallynecessary in preparing such compositions to do so either in the field orclose to the place of their application, or to prepare and store thecompositions at sufficiently low temperatures to drastically slow downthe polymerization process. In either case it is necessary to providemixing and dispensing equipment for preparing the composition and forplacing the same in applicators such as cartridges and the like andhoses and the like.

Heretofore, such equipment has been constructed and operated on batchprinciples. Indeed, preparation of such compositions on other than abatch basis has not heretofore appeared to be feasible because of thelack of economical and practical ways and means for doing so, especiallywhen dealing with components and compositions of high consistencies.Only in batch type equipment has it been practical to obtain the properproportions of the components and to obtain sufiicient intimate mixingof the components. On the other hand batch type equipment has a numberof disadvantages.

One disadvantage results from the fact that batch mixing and dispensingequipment involves a considerable amount of machinery and manpower.Moreover, mix times are lengthy.

Another disadvantage arises out of the fact that in order for theprocedure to be economical each batch must be of substantial quantity.On the other hand, the quantity of composition in each batch cannot betoo large relative to the rate at which the composition is dispensed orused. Otherwise, before the entire batch can be dispensed or used asubstantial portion of the batch may set up or harden or change in otherproperties on which there are maximum and minimum limitations and haveto be dumped. In those cases where large heats of reaction are releasedbecause of chemical reaction between the components being mixed, thetotal quantity of the batch cannot be too large for the reason that thecomposition may become scorched or otherwise heat damaged. Even thepresence of cooling means may not be adequate and in this regard it maybe observed that cooling equipment in combination with batch mixing anddispensing equipment leads to such a costly investment that fairly largebatches must be made in order to obtain the most economical use of theequipment.

Still another disadvantage with batching equipment arises out of thedifiiculty in excluding air from the components and composition inmixing and dispensing the same. Air inclusion or entrapment in the mixand resultant composition is to be avoided in a number of instances.

tent O nozzle of the machine.

There is, therefore, a need for ways and means for continuouslypreparing and dispensing composition on demand with air excluded andrapid heat removal without having to prepare the same in batches.

Attempts have been made to satisfy this need but without notablesuccess. The equipment proposed has been deficient for a number ofreasons. One reason is due to the inability of such equipment to providesufficient and adequate mixing of the components. Another reason is thecomplicated and costly structure involved. Still another reason is thedifliculty in cleaning the equipment after it has been shut down. Afurther reason is the lack of positive flow stoppage, which lack resultsin drooling of composition from the dispenser part or Otherdisadvantages exist.

A general object of this invention is to provide a mixing and dispensingmachine which has none of the noted disadvantages.

More particularly, it is an object of this invention to provide a demandmixing and dispensing machine. Stated another way, it is an object ofthis invention to provide a mixing and dispensing machine which will mixcomponents and dispense the resultant composition as needed without alarge quantity of the composition being in the machine.

Still another object of this invention is to provide a demand mixing anddispensing machine which will in timately and sufliciently mix togetherthe components and dispense the resultant composition particularly whenone or more of the components and the composition have a highconsistency. A particular object of this invention is to provide ademand mixing and dispensing machine which will intimately andsufficiently mix together the components and dispense the resultantcomposition regardless of the consistency of the components andcomposition.

Still other objects of this invention are to provide such a machine witha relatively simple structure and one .which can be readily taken apartfor service and maintenance and for cleaning when the machine has beenshut down.

These and other objects which may appear as this specification proceedsare achieved by this invention.

In summary, this invention comprises a machine for preparing anddispensing on demand a composition com prising at least a mixture of atleast two pumpable components without having first to form saidcomposition in batches. The machine of this invention is based on theconcept of a mixing chamber having a back end with an inlet for each ofthe components and a front end with a relatively constructed outlet forthe composition. Within the chamber are mixing means. Means are providedfor simultaneously stopping the flow of components through the chamberinlets and composition through the chamber outlet when it is desired tostop the machine from dispensing composition.

In the narrower aspects of this invention there is employed the conceptof the mixing means being arranged and adapted to function transverselyto the general flow through the chamber of components and composition.Still another concept is that of the mixing chamber wall transverselyfrom one end to the other conforming to the mixing means. A mostimportant concept is that of the mixing means being adapted to applykneading and shear forces to the components entering the mixing chamberand to the composition thus formed, to continuously impel components andcomposition from the mixing chamber walls inwardly and to impelcomposition through the chamber to the outlet thereof.

Another concept employed in the more specific aspects of this inventionis that of a dispenser structure which actuates the flow stoppage meansfor both the components and composition.

Still another concept involved in the more specific aspects of thisinvention is that of a mounting and service block and interconnectingconduits in combination with a readily demountable, readily dismantled,mixing head which contains the mixing chamber and mixing means. Themixing head may be provided with coolant passages for passing a coolantthrough the chamber walls.

These and other concepts are present in the specific embodiment of thisinvention disclosed in the drawings which form a material part of thedisclosure.

Before turning to the drawings, however, it should be noted that in mostinstances it will be necessary to employ a component delivery system inoperating the demand mixing and dispensing machine of this invention.Such a system has been developed and has functioned quitesatisfactorily. This system involves pump assemblies, one for eachcomponent, a proportioning or metering device and interconnectingconduits for each component. Each component is usually supplied in cansand drums. The pump assembly, in each case, comprises a plate whichconforms in plan view to the interior of the correponding componentcontainer and which has a sliding fit with the interior wall of thecontainer. Mounted on the plate is a pump, the intake of which iscoupled by a conduit to an opening through the plate. The pump dischargeis coupled by a conduit, such as a hose and the like, to thecorresponding intake of the metering device. The corresponding outlet ofthe metering device is coupled by a conduit to the mixing and dispensingmachine of this invention. To prepare the system for use the lids of therespective containers are removed and the corresponding plates placed onthe top. surface of the liquid. The system functions to deliverseparately each component in proper proportion to the others and in airfree condition to the mixing and dispensing machine.

Turning now to the drawings, it will be observed that FIG. 1 is a frontend view of a prefer-red embodiment of the demand mixing and dispensingmachine of this invention;

FIG. 2 is a plan View of the machine of FIG. 1, which view shows themixing head and a portion of the service block sectioned as indicated bythe sectioning plane 22 of FIG. 1;

FIG. 3 is a cross sectional view of the machine of FIG. 1, which viewhas been taken as indicated by the sectioning planes 3-3 of FIG. 1 andof FIG. 2;

FIG. 4 is a cross sectional view of the front end of the mixing head ofthe machine of FIG. 1, which view has been taken as indicated by thesectioning planes 4-4 of FIG. 3;

PEG. 5 is still another cross sectional view of the region of the frontend of the machine of FIG. 1, which view has been taken as indicated bythe sectioning plane 5-5 of FIG. 2;

FIG. 6 is a cross sectional view of the drive assembly of the machine,which view has been taken as indicated by the sectioning plane 6-6 ofFIG. 3 and which has been partially cut away to reveal internalstructure;

FIG. 7 is a longitudinal sectional view of the drive assembly, taken asindicated by the sectioning plane 7-7 of FIG. 6;

FIG. 8 is still another longitudinal sectional view of the driveassembly, taken as indicated by the sectioning plane 88 of FIG. 6;

FIG. 9 is a cross sectional view of the mounting and service block ofthe machine, taken as indicated by the sectioning plane 99 of FIGS. 2and 3;

FIG. 10 is plan view of the front end of the mixing head and of thedispenser assembly of the machine, which view has been taken asindicated by the plane 1ii10 of FIGS. 1 and 3;

FIG. 11 is a longitudinal sectional view of the front end of the mixinghead and of the dispenser assembly of 4 the machine, which has beentaken as indicated by the sectioning planes 11-11 of FIGS. 1, 2 and 10;and

FIG. 12 is a schematic of the pressure air system employed to operatethe machine.

In greater detail, FIGS. 1, 2 and 3 of the drawings disclose a demandmixing and dispensing machine 20 which involves a number ofinter-related structural assemblies. In particular the machine 20comprises a mixing head assembly 22 and a mounting and service blockassembly 2 3.

The mixing head assembly 22 comprises a mixing head structure 26 and adispenser structure 28.

The mixing head structure 26 comprises a body member 30, a back endclosure member 32, a front end closure member 34 and a pair of rotors 36and 38. The body member as shown in FIGS. 2, 3 and 5 is in the form of ablock, square in cross section and longitudinally rectangular, which isturned on edge. Extending from one end of the body member 36 to theother end generally in alignment with the longitudinal axis of the bodymember 30 are a pair of overlapping cylindrical apertures 40 and 42 anda pair of coolant passageways 44 and 46. The apertures 40 and 42 and thepassageways 44 and 46 are open at each end of the mixing head bodymember 30. The mixer body at each end about and between the overlappingaperture openings, however, is recessed in order to accommodate suitableseals or gaskets 48 and an end closure plate embossment. The coolantpassageways 44 and 46, at least in the region of the back end of themixing head body member 30, have a larger diameter than the centralportions thereof whereby coolant conduit receiving, annular spaces areprovided.

The back end closure member 32, shown in FIGS. 9, 2 and 3, comprises anembossment 50 having parallel sides and semi-circular ends which conformin size to the outer peripheral portions of the apertures 40 and 42through the mixing head body member 30. Disposed through the embossment50 are the component inlet orifices 56 and 58 which are positioned so asto be as close as possible to the longitudinal center line of the mixerhead body member 30. In addition, each orifice 56 and 5'8 is positionedfor direct communication with the corresponding apertures '40 and 42 inthe mixing head body member 30.

The back end closure member 32 further comprises lateral flanges 60 withlongitudinally aligned, tie rod receiving openings 62 therethrough.

The front end closure member 34 comprises a plate having on the backside thereof (see FIG. 4) an embossment 64 having parallel sides andsemi-circula-r ends conforming to the outer peripheral portion of theapertures 40 and d2 of the mixing head body member 30. Within theembossment 64 is a recess 66 in which is seated a rotor bearing plate68. In addition, there is provided in the embossment 64 a dischargeoutlet slot 70 which is partially under the rotor bearing plate 68. Onboth sides of the embossment 64 (see FIGS. 3 and 4) and spaced therefromare coolant passages 72 and 74 which are in alignment with the frontends of the coolant passageways '44 and 46 in the mixing head bodymember 30 and which are interconnected by a coolant return passageway 76which is positioned on the front side of and spaced from, the recess 66.On the front side of the front end closure member 34 there is providedan embossment 78'. Disposed through the embossment 7 8 is a transverse,normally vertical, dispenser assembly tube receiving hole 80. Betweenthe outlet slot 70 and the dispenser assembly. tube receiving hole 80there is provided an interconnecting, discharge passageway 82. The frontend closure member 34 is likewise provided with a pair of laterallyextending flanges 83 with tie rod receiving openings 85 therethroughwhich are normally in alignment with the tie rod openings 62 through theflanges 66 of the back end closure member 32.

With the back and front end closure members 32 and 34 in position on thebody member -30 of the mixing head structure 26 the cylindricalapertures 40 and 42 are closed at both ends wherefore, an air tightmixing chamber 84 is formed with component inlets 56 and 58 in theregion of the back end thereof and a composition discharge outlet '70 inthe region of the front end thereof. Within the mixing chamber are therotors 36 and 38.

Each rotor 36 and 38 comprises a rotor shaft 86 which is normallydisposed in coaxial alignment with the longitudinal axis of the aperturein which the rotor is positioned. With the mixing head structure 26assembled one end of each rotor shaft 86 is rotatably seated in acorresponding recess of the rotor bearing plate 68. See FIGS. 2 and 3.The shaft 86 in each case extends therefrom through the correspondingcylindrical apertures 40' and 42 and corresponding bushings 54 in theback end closure member 32, and terminates in an irregularly shaped endwithin the mounting and service block assernbly 24. Each rotor shaft 86comprises along the length thereof within the apertures 40 and 42 andthus the mixing chamber 84 transverse, circular vanes 88 and 90 whichhave outside diameters such that the circumferential periphery of eachvane under normal operative conditions is adjacent the wall surfacedefining the corresponding cylindrical aperture but not in contacttherewith. In other words, the outside diameter of each vane 88 and 90is slightly less than the diameter of the adjacent wall surface. Thevanes 88 and 90 of one rotor 36 are interleaved or interposed betweenthe overlapping portions of the vanes 88 and 90 of the other rotor 38.In general, each vane 88 and 90 comprises an opening therethrough topermit the passage of components and composition from the back end ofthe mixing chamber 84 to the front end of the mixing chamber 84. Theopenings are preferably arranged and shaped to provide not only kneadingand shearing action but also forward impelling action.

A satisfactory arrangement is to provide the first and last vanes 88 ofeach rotor 36 and 38 with an annular row of circular openings 92. Theintermediate vanes 90 between the first and last vanes 88 are providedwith openings in the form of notches 94 which extend from adjacent therotor shaft 86 to the circumferential periphery of the vanes 90 so thatin an edge view of the vanes 90, as in FIG. 2, the appearance issomewhat like that of a dado blade. Preferably, the center line of eachnotch 94 of the intermediate vanes 90 is at an acute angle to the radiusextending thereto at the outside diameter of the vane and preferably thecenter line of the notch 94 is at an acute angle with a line tangent tothe rotor shaft 86 with the acute angle facing in the general directionof normal rotation of the rotor shaft as in FIG. 5. In employing vanes90 with notches 94, it is preferred to angularly displace the notches 94of one vane 90 from the notches 94 of the vanes on each side thereof.The reason is to minimize if not prevent short circuiting of componentsto the discharge outlet 70 of the mixing chamber 84.

The dispenser structure 28, shown in FIGS. 1, 2, l0 and 11 comprises abushing 96, a dispenser 98 and a pilot valve 102.

The bushing 96, cylindrical in shape, is disposed in the transverse,dispenser assembly tube receiving hole 80 through the em bossment 78 ofthe front end closure member 34. The bushing 96 is so disposed in thehole 80 in friction fit. On the side of the bushing 96 and in alignmentand in conformity with the outlet of the discharge passageway 82 throughthe front end closure member 34 is a slot 102.

The dispenser 98 comprises a tube member 104, a threaded, removable plug106, a nozzle member 108 and a lever arm 110. The tube member 104 isjoined at one end as by brazing to the nozzle member 108 and at theother end is normally threadedly engaged by the plug 106. The tubemember 104 and nozzle member 108 together provide a composition flowpassageway 112 with an orifice 114 at the outer end thereof. Thepassageway 114 has a normally vertical portion in the tube member 104and a normally horizontal portion in the nozzle member 108. The tubemember 104 is disposed in sliding or rotatable fit through the bushing28. In the side of the tube member 104 and displaced by a significantare from the slot 102 of the bushing 96 when the tube member is in nodispense position is a slot 116 which conforms in shape to the slot 102and outlet of the discharge passageway 82 in the front end closuremember 64. When the tube member 104 is rotated to dispense position, theslot 116 is in alignment with the slot 102 and said outlet. The orifice114 at the end of the flow passageway 112 is defined by an annular lip118. The lip 118 is provided for receiving the tip of cartridges and thelike to be filled with the composition and for receiving hoses and thelike for conveying the composition to an applicator head. The lever armextends forwardly from, and above, the dispenser nozzle member 108. Theback end thereof is seated in a corresponding slot 120 in the upper sideof the nozzle member 108 and is secured thereto as by a set screw 122through the nozzle member.

The dispenser 98 is rotatable on a vertical axis through theaforementioned significant are. In the embodiment shown in FIG. 10, thisare is about 15. With the center line of the orifice 114 of the nozzlemember 108 in parallel with the 'longitudinal center line of the mixinghead structure 26 the dispenser 98 in the embodiment shown in thedrawings is in the no dispense position, which is to say, the positionin which no components are introduced into the mixing chamber 84, inwhich no composition is impelled through the chamber 84 and in which thetube member 104, which functions as a valve, closes the outlet of thechamber discharge passageway 82. When the dispenser 98 is rotatedthrough the selected arc, it is then in dispense position. In suchposition, components flow into the mixing chamber 84 and composition isformed,

discharged through the outlet of the discharge passageway 82 anddispensed through the dispenser structure 28. Since it is intended thatthe position of the dispenser nozzle 98 determine whether or not themachine 20 is in operation, the pilot valve 100 is provided and theoutside of the dispenser nozzle 98 is characterized by a cam surface 124in the region of the back end which, upon rotation of the dispensernozzle 98 through the selected are of rotation, travels the greatestdistance. The pilot valve 100 is of the poppet type. It comprises apressure air escape vent 126. The valve 100 is disposed generally in theplane of said cam surface and comprises a push button member or cammember 128 which is adjacent the cam surface 124. The cam surface 124 isarranged so that upon rotation of the dispenser 98, it will cause thecam member 128 to be depressed into the poppet valve casing and actuatethe valve therein to release pressure air from the pressure air conduitto which the valve 100 is coupled.

The mounting and service block assembly 24, positioned generallyrearwardly of the mixing head assembly 22, as shown in FIGS. 2 and 3,comprises a service block 130, a pair of tie rods 132, a pair of capnuts 134 for the front ends of the tie rods 132, interconnectingcomponent tubes 136 and 138, interconnecting coolant tubes 140 and 142,a rotor drive assembly 144 and component flow shut-off valves 146 and148. The service block 130 is held spaced apart from the mixing headassembly 22 by spacer means 212 positioned on the tie rods 132 as shownin FIG. 2.

The service block 130 comprises, as shown in FIG. 3, component flowpassageways 150 and 152, coolant flow passageways 154 and 156, on theback side thereof a tapped hole 158 for a drive assembly mounting boltand, as shown in FIG. 2, tapped holes 160 on the front side thereof forthe tie rods 132, and shaft alleys 162 and 164.

The component flow passageways 150 and 152 have laterally disposedinlets and longitudinally aligned outlets which, when the block 130 isin position, are in alignment with the corresponding component orifices56 and 58. The inlets to the component flow passageways 150 and 152 haveseated therein in threaded engagement the corresponding component flowshut-off valves 146 and 148. The outlets have seated therein in threadedengagement the inlet ends of the corresponding interconnecting componenttubes 136 and 138. The outlet ends of the component tubes, provided withO-ring seals 166, are seated in sliding fit in the correspondingcomponent inlet orifices 56 and 58 through the back end closure member32. The coolant flow passageways 154 and 156 have front and back sideinlets and outlets, which, when the block 130 is in position, are inalignment with the coolant passageways 44 and 46 of the mixing head bodymember 30.

The coolant flow passageways 154 and 156 at the back side ends thereofhave seated therein in threaded engagement corresponding coolant inflowand outflow conduits 168 and 170. On the front side of the service block130 the coolant passageways 154 and 156 have seated therein in threadedengagement the back end of the coolant flow tubes 140 and 142, the frontends of which are mounted in sliding fit in the annular recessed endportions of the coolant passageways 44 and 46 in the mixing head bodymember 30. To prevent leakage of coolant past the outer walls of thecoolant tubes 140 and 142 and the inner wall of the mixing head bodydefining the annular recessed portions of the coolant passageways 44 and46 in the mixer head body 30, the front ends of the coolant tubes areencircled by O-ring seals 172.

The rotor drive assembly 144, mounted to the service block 130 by way ofa mounting bolt 173, comprises an air motor 174 with a main rotor driveshaft 176, a tachometer drive gear 180, a tachometer driven gear 182, adrive sprocket 184, a chain drive 186, a driven sprocket 188 and adriven rotor drive shaft 190.

The main rotor drive shaft 176 extends forwardly from the air motor 174through the base of the tachometer 178, through the chain drive housing192 and into the corresponding shaft alley 162 of the service block 130.In the base of the tachometer, the main rotor drive shaft 176 hasmounted thereon a tachometer drive gear 180 which is meshed with thetachometer driven gear 182 on the tachometer shaft. In the chain drivehousing 192 the main rotor drive shaft 176 has mounted thereon the thedrive sprocket 184. About the drive sprocket 184 and about the drivensprocket 188 is the chain drive 186. The driven sprocket 188 is mountedon the driven rotor drive shaft 190 which extends longitudinally fromthe chain drive housing 192 into the corresponding shaft alley 164 ofthe service block. Inside the service block 130 the front ends of therotor drive shaft 176 and the rotor driven shaft 190 comprise socketmembers 194 and 196 for receiving the corresponding ends of the rotorshafts 86. The socket members 194 and 196 in end view conform in shapeto the ends of the rotor shafts 86. This enables the rotor shafts 86 tobe readily unseated therefrom. The advantage of this aspect is the easein removal of the mixing head assembly from the service block and tierod members thereof.

The air motor 174 is of a conventional type .andneed not, therefore, bedescribed in detail. The pressure air thereto is preferably suppliedthrough a conduit 197 comprising an air flow rate control valve 198 (seeFIG. 12), which is coupled to a common, pressure air conduit 290.

The component flow shut-off valves 146 and 148 as shown in FIGS. 1 and 9.are pressure air actuated. Indeed, in accordance with this invention,pressure air is supplied to each fiow shut-off valve from the common,pressure air conduit 200. The valves 146 and 148 have laterally disposedcomponent intakes which are coupled to corresponding component supplyconduits 202 and 204 which function to deliver to the machine 20components from the previously mentioned metering device.

The pressure air system for the machine 20 is diagrammaticallyillustrated in FIG. 12. It comprises a main pressure air supply conduit206, a pressure air master shut-off valve 29%, the common pressure airconduit 2%,

a pressure air bleed-off conduit 210 and the pilot valve 100. The mainpressure .air supply conduit 206 18 coupled to one side of the mastershut-off valve 288. The other side of the master valve 208 is coupled tothe common pressure air conduit 200. As long as pressure air 1s suppliedto the actuating mechanism the master valve 208 will be closed. However,if the pressure air is removed from the actuating mechanism the mastervalve 268 opens. The actuating mechanism is in combination with the airbleed-off conduit 216- which is coupled to the pilot valve 101}. Hence,when the cam member 128 of the pilot valve is depressed as by rotatingthe dispenser 93 to the dispense position, the pressure air is bled-offfrom the actuating mechanism of the master valve 208 through the pilotvalve vent 126 and the master valve 208 opens. This supplies pressureair to the air motor 174 and to the component flow shut-off valves 146and 148. The air motor 174 commences to rotate and the component flowshut-off valves 14-6 and 148 open. When the cam member 128 of the pilotvalve 160 is released as by rotating the dispenser 98 to the no dispenseposition the vent 126 of the pilot valve 109 is closed and the pressureair condition in the actuating mechanism of the master valve 298 isresumed, whereupon the same closes. The air motor 174 stops and thecomponent flow shut-off valves 146 and 148 close.

To prepare the machine 20 for use the component supply conduits 262 and204 from the metering device are coupled to the respective componentflow shut-off valves 146 and 148. The master valve 208 with the commonpressure air conduit 260 coupled thereto and to the air motor air feedconduit 197 and component flow shut-off valves 146 and 148 (and also tothe metering device and component feed pumps) is coupled to the mainpressure air supply conduit 206. The mixing head assembly 22 inassembled condition is mounted on the mounting and service blockassembly 24 with the tie rods 132 passing through the corresponding tierod openings 62 and 85, the component tubes 136 and 138 seated in thecorresponding component orifices 5'6 and 58 of the back end closuremember 32 and the coolant tubes 141 and 142 seated in the back ends ofthe coolant passageways 44 and 46 of the mixing head body member 30. Thecap nuts 134 are mounted on the front ends of the tie rods 132 andtightened down, thereby making the mixing head structure 26 airtight.With the lever arm in no dispense position, the coolant flow is turnedon and the 'master pressure air valve 208 is turned on. The lever arm11% is then rotated to dispense position whereupon components flow intothe mixing chamber 84- and the rotors 36 and 38 rotate. When compositionappears at the dispenser outlet 114 and air in the machine 21'3 appearsto be expelled therefrom, the lever arm 110 is returned to no dispenseposition. The machine 20 is now ready for normal operation.

To use the machine 20, a hose type applicator and the like or acartridge type applicator and the like is mounted on the annular lip 118of the dispenser structure 28 and the lever arm 11%) rotated to dispensepositron. When the cartridge is full or the particular job finished orwhen it is desired to stop the machine 20, the lever arm 110 is merelyreturned to no dispense posi- If, during operative conditions, thecomposition does not appear to be sufiiciently mixed, the air flow ratecontrol valve 198 on the air motor feed conduit 197 is turned until thetachometer 178 indicates a lower rate of rotation of the air motor driveshaft 176. If the composition is at a higher than specified consistencyfor the composition, the coolant flow rate should be increased and, ifthis is not sufficient, the air flow rate control valve 198 turned untilthe tachometer 17S registers a higher rate of rotation of the air motordrive shaft 176. These steps will usually sufiice unless the formulationof the composition is faulty or the components are off specification.

When the machine 20 is shut down for any length of time it isrecommended that the mixing head structure 26 and dispenser structure 23be dismantled and cleaned. To do this, the master air valve 208 andcoolant flow are first turned oil. Then the cap nuts 134 are removedfrom the tie rods and the mixing head assembly 22 removed. The mixinghead assembly 22 is then dismantled including the removal of thedispenser assembly plug 106, and cleaned. This it Will be seen isreadily and easily accomplished since the assembly is no longer heldtogether and the various structural elements can simply be taken apart.When the cleaning operation is completed the various structural elementsof the mixing head assembly 22 are assembled and placed into positionand the mixing head assembly 22 mounted on the mounting and serviceblock assembly 24 as already described.

Thus, there is provided a mixing and dispensing machine for continuouslymixing together components to form a composition and for dispensing thecomposition.

A major feature of advantage of this machine is that components aremixed together substantially only as needed. In other Words, theinventory of composition in the machine under normal operativeconditions at any one moment is quite low. Wastage of composition uponstarting up and shutting down of the machine is insignificant.

Another major feature of advantage of the machine of this inventionresides in the action of the rotors 36 and 38. Because of theconfiguration of the mixing chamber 84, and of the arrangement of therotors 36 and 38 therein, all of the components and composition aresubjected to intense kneading and shearing action and to impellingaction throughout the length of the chamber 84. Moreover, underoperative conditions, components and composition at the chamber wallsare continuously wiped therefrom and impelled inwardly to commingle withthe components and composition inwardly of the chamber Walls.Furthermore, this action and these eflects are obtained regardless ofthe consistencies of the components and the resultant composition. Inthis regard the machine of this invention is particularly useful inpreparing composition of high consistencies.

Still another feature of advantage of the machine of this inventionresides in the air free mixing aspect thereof. Because the machine 20presents a completely closed and pressurized system, air entrapment andmaterial contarnination due to air exposure is eliminated.

Yet another feature of advantage is that the machine is completely airpowered, which not only enhances its value from a standpoint of economyof operation but also from the standpoint of safety.

A most important advantage of the machine of this invention is the easewith which the mixing time of the composition can be controlled. Byregulating the coolant flow rate and by regulating the speed of the airmotor 174- highly sensitive and accurate control of the required mixingtime can be obtained.

Still another important feature of advantage of this invention residesin the combination of the component flow shut-01f valves 146 and 14-8,the air motor 174 and the dispenser valve, represented by the dispensernozzle tube member 104, together with the pressure air control systemwhich includes the pilot valve 100. When the lever arm 116 is rotatedfrom dispense position to no dispense position positive and immediatestopping of component and composition flows is obtained. This preventsdrooling of composition from the dispenser orifice 114. This alsoeliminates back mixing of components and confines composition to themixing chamber 84.

Other major advantages of the machine of this invention are the smallnumber of parts actually exposed to the composition, the ease with whichthe same may be dismantled and disassembled for cleaning and the readyaccessibility to the interior surfaces exposed to the composition.

These and other meritorious features, advantages and embodiments will beapparent to those in the exercise of ordinary skill in the art uponreading the foregoing description. For example, the specific embodimentdescribed can be readily modified to handle three and more components.Instead of a pressure air system an electrical system can be used. Itshould be understood, therefore, that the scope of this invention isdefined by the appended claims rather than by the foregoing descriptionand that all embodiments and variations and modifications thereof, whichincorporate the true spirit and essential characteristics of thisinvention, are intended to be embraced by those claims unless expresslyexcluded by their language.

We claim:

1. A demand mixing machine for mixing together as needed at least twopumpable components and for dispensing the resultant composition withouta substantial back-log of composition in the machine which comprises: amixing chamber having a back end and a front end with an inlet for eachof said components in the region of said back end and a relativelyconstricted outlet in the region of said front end for said composition,whereby the overall flow path of said components and. composition insaid chamber is from the region of said back end to the region of saidfront end, said chamber from the region of said back end to the regionof said front end having the shape of a pair of overlapping,longitudinally aligned cylinders whereby said chamber has a pair oflongitudinally aligned axes of radial symmetry; mixing means in saidchamber transversely arranged to said overall flow path, said mixingmeans comprising a pair of longitudinal shaft means in coaxial alignmentwith the corresponding longitudinal axis of radial symmetry andextending through openings through the back end of said mixing chamber,

each shaft means inside said mixing chamber comprising a plurality oftransversely disposed, parallel, generally radially symmetrical vanemeans interposed between the vane means of the other shaft means, eachof said vane meanshaving an outside diameter slightly less than theinside diameter of the cylinder portion of the mixing chamber in whichsaid vane means is disposed, at least some of said vane means of eachshaft means having openings therethrough disposed at an angle withrespect to the rotation of the shaft means to impel componentstransversely radially inwardly of the overall flow path and from onecylindrically shaped portion of the mixing chamber to the othercylindrically shaped portion thereof; prime mover means for rotatingsaid shaft means; and separate conduit means for each of said componentsfrom the supply sources thereof to the chamber inlets therefor.

2. A demand mixing machine for mixing together as needed at least twopurnpable components and for dispensing the resultant compositionwithout a substantial backlog of composition in the machine whichcomprises: a mixing chamber having a back end and a front end with aninlet for each of said components in the region of said back end and arelatively constricted outlet in the region of said front end for saidcomposition, whereby the overall flow path of said components andcompetition in said chamber is from the region of said back end to theregion of said front end, said chamber from the region of said back endto the region of said front end having the shape of a pair ofoverlapping, longitudinally aligned cylinders whereby said chamber has apair of longitudinally aligned axes of radial symmetry; mixing andimpelling means in said chamber transversely arranged to said overallflow path, said mixing and impelling means comprising a pair oflongitudinal shaft means in coaxial alignment with the correspondinglongitudinal axis of radial symmetry and extending through openingsthrough the back end of said mixing chamber, each shaft means insidesaid mixing chamber comprising a plurality of transversely disposed,parallel, generally radially symmetrical vane means interposed betweenthe vane means of the other shaft means,

1 1 each of said vane means having an outside diameter slightly lessthan the inside diameter of the cylinder portion of the mixing chamberin which said vane means is disposed, and comprising openingstherethrough, said openings in the vane means between the first and lastvane means on each shaft means being in the form of notches angulated inthe normal direction of rotation of said vane means to impel componentsradially inwardly away from the mixing chamber wall toward the shaftmeans; prime mover means for rotating said shaft means; separate conduitmeans for each of said components from the supply sources thereof to thechamber inlets therefor; and discharge valve means in combination withsaid relatively constricted discharge outlet.

3. A demand mixing and dispensing machine for mixing together as neededat least two pumpable components and for dispensing the resultantcomposition without a substantial backlog of composition in the machinewhich comprises: a mixing chamber having a back end and a front end withan inlet for each of said components in the region of said back end anda relatively constricted outlet in the region of said front end for saidcomposition, whereby the overall flow path of said components andcomposition in said chamber is from the region of said back end to theregion of said front end, said chamber from the region of said back endto the region of said front end having the shape of a pair ofoverlapping, longitudinally aligned cylinders whereby said chambers hasa pair of longitudinally aligned axes of radial symmetry; mixing andimpelling means in said chamber transversely arranged to said overallflow path, said mixing and impelling means comprising a pair oflongitudinal shaft means in coaxial alignment with the correspondinglongitudinal axis of radial symmetry and extending through openingsthrough the back end of said mixing chamber, each shaft means insidesaid mixing chamber comprising a plurality of transversely disposed,parallel, generally radially symmetrical vane means interposed betweenthe vane means of the other shaft means, each of said vane means havingan outside diameter slightly less than the inside diameter of thecylinder portion of the mixing chamber in which said vane means isdisposed, and comprising openings therethrough, said openings in thevane means between the first and last vane means on each shaft meansbeing in the form of notches angulated in the normal direction ofrotation of said vane means to impel components radially inwardly fromthe periphery of the vane means toward the center of the shaft means;prime mover means for rotating said shaft means; separate conduit meansfor each of said components from the supply sources thereof to thechamber inlets therefor, each of said conduit means comprising flowshutoff valve means; dispenser means in combination with said dischargeoutlet, said dispenser means comprising discharge valve meansoperatively connected with said flow shut-off valve means and said primemover means whereby said flow shut-off valve means are closed and saidprime mover means is non-operative when said discharge valve means isclosed and said flow shutoff valve means are open and said prime movermeans is in operation when said discharge valve means is open.

4. A demanded mixing and dispensing machine for mixing together asneeded at least two pumpable components and for dispensing the resultantcomposition without a substantial back-log of composition in themachine, which comprises a mixing head assembly in combination with aservice block assembly, said mixing head assembly comprising: a bodymember having therein a mixing chamber in the form of a pair ofoverlapping, longitudinally aligned, side-by-side cylinders extendingfrom one end of said body member to the other; a back end closure memberhaving separate component orifices and rotor shaft passagewaystherethrough and laterally extending flanges with tie rod holestherethrough; a front end closure member having a relatively constricteddischarge passageway therethrough, laterally extending flanges with tierod holes therethrough normally in alignment with the tie rod holes ofsaid flanges of said back end closure member and on the front sidethereof dispenser means including a valve in combination with the outletof said discharge passageway; rotor means in each of said cylinderportions of said spaces comprising shaft means normally extendingthrough said shaft passageways in said back end closure member and vanemeans for applying kneading and shearing forces to components andcomposition in said chamber and for impelling said components andcomposition forwardly through said chamber; and said service blockassembly comprising: a block having tie rod members positioned thereonextending forwardly of said block, said tie rod members having mountedthereon said end closure members and said body member, spacer meansinterposed between said block and said back end closure member, shaftalleys corresponding to said rotor shaft passageways into which saidshafts extend and component flow passageways with inlets and outlets;rotor drive means with drive shafts extending into said shaft alleys andin engagement with said rotor shafts; component infeed conduits withflow shut-off valves connected to said inlets of said component flowpassageways; com-ponent flow tubes connected to said outlets of saidcomponent flow passageways and seated in said component orifices of saidback end closure member; and cap nut means for threaded engagement withthe front ends of said tie rod members and for holding said mixing headassembly together and in place on said tie rod members.

5. A demand mixing and dispensing machine for mixing together as neededat least two pumpable components and for dispensing the resultantcomposition without a substantial back-log of composition in themachine, which comprises a mixing head assembly in combination with aservice block assembly, said mixing head assembly comprising: a bodymember having therein a mixing chamber in the form of a pair ofoverlapping, longitudinally aligned, side-by-side cylinders extendingfrom one end of said body member to the other; a back end closure memberhaving separate component orifices and rotor shaft passagewaystherethrough and laterally extending flanges with tie rod holestherethrough; a front end closure member having a relatively constricteddischarge passageway therethrough, laterally extending flanges with tierod holes therethrough normally in alignment with the tie rod holes ofsaid flanges of said back end closure member and on the front sidethereof dispenser means including a valve in combination with the outletof said discharge passageway, said dispenser means comprising anembossment portion of said front end closure member with a transversepassageway along the side of which said discharge passageway has anoutlet, a rotatable tube seated in said transverse passageway, said tubehaving a lateral opening corresponding to said discharge passagewayoutlet and a head with a dispenser orifice and passageway extendingthereto from said tube, and means for rotating said tube and head from ano-dispense position to a dispense position whereat said lateral openingin said tube is in register with said discharge passageway outlet; rotormeans in each of said cylinder portions of said spaces comprising shaftmeans normally extending through said shaft passageways in said back endclosure member and vane means for applying kneading and shearing forcesto components and composition in said chamber and for impelling saidcomponents and composition forwardly through said chamber; and saidservice block assembly comprising: a block having tie rod memberspositioned thereon extending forwardly of said block, said tie rodmembers having mounted thereon said end closure members and said bodymember, spacer means interposed between said block and said back endclosure member, shaft alleys corresponding to said rotor shaftpassageways into which said shafts extend and component flow passagewayswith inlets and outlets; rotor drive means with drive shafts extendinginto said shaft alleys and in engagement with said rotor shafts;component infeed conduits with flow shut-off valves connected to saidinlets of said component flow passageways; component fiow tubesconnected to said outlets of said component flow passageways and seatedin said component orifices of said back end closure member; and cap nutmeans for threaded engagement with the front ends of said tie rodmembers and for holding said mixing head assembly together and in placeon said tie rod members.

6. A demand mixing and dispensing machine for mixing together as neededat least two pumpable components and for dispensing the resultantcomposition without a substantial backlog of composition in the machine,which comprises a mixing head assembly in combination with a serviceblock assembly, said mixing head assembly comprising: a body memberhaving therein a mixing chamber in the form of a pair of overlapping,longitudinally aligned, side by-side cylinders extending from one end ofsaid body member to the other; a back end closure member having separatecomponent orifices and rotor shaft passageways therethrough andlaterally extending flanges with tie rod holes therethrough; a front endclosure member having a relatively constricted discharge passagewaytherethrough, laterally extending flanges with tie rod holestherethrough normally in alignment with the tie rod holes of saidflanges of said back end closure member and on the front side thereofdispenser means including a valve in combination with the outlet of saiddischarge passageway, said dispenser means comprising an embossmentportion of said front end closure member with a transverse passagewayalong the side of which said discharge passageway has an outlet, arotatable tube seated in said transverse passageway, said tube having alateral opening corresponding to said discharge passageway outlet and ahead with a dispenser orifice and passageway extending thereto from saidtube, said head having on the outside thereof a cam surface with aprotruding portion, means for rotating said tube and head from ano-dispense position to a dispense position whereat said lateral openingin said tube is in register with said discharge passageway outlet, and apilot valve means with a cam positioned relative to said cam surface,said cam being depressed into said pilot valve means by said protrudingportion of said cam surface when said head is in dispense position andbeing extended from said pilot valve means when said head is inno-dispense position; rotor means in each of said cylinder portions ofsaid spaces comprising shaft means normally extending through said shaftpassageways in said back end closure member and vane means for applyingkneading and shearing forces to components and composition in saidchamber and for impelling said components and composition forwardlythrough said chamber; and said service block assembly comprising: ablock having tie rod members positioned thereon extending forwardly ofsaid block, said tie rod members having mounted thereon said end closuremembers and said body member, spacer means interposed between said blockand said back end closure member, shaft alleys corresponding to saidrotor shaft passageways into which said shafts extend and component flowpassageways with inlets and outlets; rotor drive means with drive shaftsextending into said shaft alleys and in engagement with said rotorshafts; component infeed conduits with flow shut-off valves connected tosaid inlets of said component flow passageways; component flow tubesconnected to said outlets of said component flow passageways and seatedin said component orifices of said back end closure member; means incombination with said flow shut-off valve means and said rotor drivemeans and responsive to the cam of said pilot valve means for causingsaid shut-off valve means to open and said rotor drive means to operatewhen said cam is depressed and for causing said shut-off valve means toclose and said rotor drive means to be inoperative when said cam isextended; and cap nut means for threaded engagement with the front endsof said tie rod members and for holding said mixing head assemblytogether and in place on said tie rod members.

7. A demand mixing and dispensing machine according to claim 6 whereinsaid body member comprises coolant flow passages with an inlet and anoutlet at the back end thereof, said service block comprises coolantpassageways in alignment with said inlet and outlet and said serviceblock assembly includes coolant fiow tubes extending forwardly from saidpassageway into and in sliding fit with said inlet and outlet.

8. A demand mixing and dispensing machine for mixing together as neededat least two pumpable components and for dispensing the resultantcomposition without a substantial backlog of composition in the machine,which comprises: a mixing chamber having a back end with an inlet foreach of said components and the front end with a relatively constricteddischarge outlet for said composition whereby the overall flow path ofsaid components and composition is from the region of said back end tothe region of said front end; mixing and impelling means in said chamberarranged transversely to said overall flow path; motive means connectedto said mixing and impelling means; separate feed conduits for each ofsaid components to the mixing chamber inlets therefor, each of saidconduits having flow shut-off valves therein for posi tively stopping orallowing flow to the mixing chamber; dispenser means cooperating withsaid outlet, said dispenser means including a discharge valve and acontrol device, said flow shut-off valves having actuating means foropening and closing same connected to said control device, and saidmotive means connected to said control device, whereby upon closing saiddischarge valve said control device is actuated to close said flowshut-ofi valves and stop said motive means, and upon opening saiddischarge valve said control device is actuated to open said flowshut-off valves and start said motive means.

9. A demand mixing and dispensing machine essentially as defined inclaim 8 characterized in that said motive means is a fluid pressuremotor; said actuating means for opening and closing the flow shut-ofivalves is a fluid pressure motor; and said control device is a fluidpressure pilot valve.

10. A demand mixing and dispensing machine for mixing together as neededat least two pumpalble components and for dispensing the resultantcomposition without a substantial backlog of composition in the machine,which comprises: a mixing chamber having a back end and a front end withan inlet for each of said components in the region of said back end anda relatively constricted discharge outlet in the region of said frontend for said composition, whereby the overall fiow path of saidcomponents and composition in said chamber is from the region of saidback end to the region of said front end; mixing and impelling means insaid chamber transversely arranged to said overall flow path andoperable to mix together components in the chamber; separate conduitmeans for each of said components from supply sources thereof to thechamber inlets therefor, each of said conduit means comprising positiveacting flow shut-oil valve means for allowing or positively preventingcomponent flow into said mixing chamber; and dispenser nozzle means incombination with said outlet, said dispenser nozzle means includingdischarge valve means; and a control system coupled to said mixing andimpelling means and to said positive acting flow shut-off valve meansand to said discharge valve means with said flow shut-off valve meanswhereby said flow shut-off valve means are closed and said mixing andimpelling means are stopped when said discharge valve means is closedand said flow shutoff valves are open and said mixing and impellingmeans are started when said discharge valve means is open.

11. A mixing head assembly for a demand mixing and 15 dispensing machinecharacterized by a service block assembly and a mixing head assembly,which comprises: a body member having therein a mixing chamber in theform of a pair of overlapping, longitudinally aligned, side-by-sidecylinder portions extending from one end of said body member to theother; a back end closure member having a separate component orifice foreach cylinder portion and a rotor shaft passageway therethrough for eachcylinder portion and laterally extending flanges with tie rod holestherethrough; a front end closure member having a relatively constricteddischarge passageway therethrough for communication with said cylinderportions, laterally extending flanges with tie rod holes therethroughnormally in alignment with the tie rod holes of said flanges of saidback end closure member and on the front side thereof dispenser meansincluding a valve in combination with the outlet of said dischargepassageway; rotor means in each of said cylinder portions comprisingshaft means normally extending through said shaft passageways in saidback end closure member and interleaved vane means in said cylinderportions extending from and carried by said shaft means for applyingkneading and shearing forces to components and composition in saidchamber, said vane means having component impelling surface portionsdisposed at an angle to the direction of rotation of the shaft means tosweep component from adjacent the Walls of the cylindrical portionsinwardly toward the shaft means and transfer component from onecylindrical portion to the other cylindrical portion during overall flowof the components from back closure member toward the front closuremember.

References Cited in the file of this patent UNITED STATES PATENTS2,668,756 Carney Feb. 9, 1954 2,758,915 Vodonik Aug. 14, 1956 2,847,196Franklin et al Aug. 12, 1958 2,974,830 Hood Mar. 14, 1961

